Abstract

Explainable machine learning methods have attracted increased interest in recent years. In this work, we pose and study the niche detection problem, which imposes an explainable lens on the classical problem of co-clustering interactions across two modes. In the niche detection problem, our goal is to identify niches, or co-clusters with node-attribute oriented explanations. Niche detection is applicable to many social content consumption scenarios, where an end goal is to describe and distill high-level insights about user-content associations: not only that certain users like certain types of content, but rather the types of users and content, explained via node attributes. Some examples are an e-commerce platform with who-buys-what interactions and user and product attributes, or a mobile call platform with who-calls-whom interactions and user attributes. Discovering and characterizing niches has powerful implications for user behavior understanding, as well as marketing and targeted content production. Unlike prior works, ours focuses on the intersection of explainable methods and co-clustering. First, we formalize the niche detection problem and discuss preliminaries. Next, we design an end-to-end framework, NED, which operates in two steps: discovering co-clusters of user behaviors based on interaction densities, and explaining them using attributes of involved nodes. Finally, we show experimental results on several public datasets, as well as a large-scale industrial dataset from Snapchat, demonstrating that NED improves in both co-clustering (20% accuracy) and explanation-related objectives (12% average precision) compared to state-of-the-art methods.